As shown in FIG. 7 which is a perspective view, an LCD device 100 having a so-called liquid crystal cell 110 has a structure in which a first substrate 101 and a second substrate 102, which have different sizes from each other, are bonded together with a frame-shaped sealant interposed therebetween. The LCD device 100 has various electrodes on its opposing surfaces.
As shown in FIG. 8, which is an enlarged plan view of a region X in FIG. 7, the first substrate 101 and the second substrate 102 are held by spacers (not shown) so as to maintain a predetermined gap therebetween, and the gap between the first substrate 101 and the second substrate 102 is filled with a liquid crystal material. In some cases, the spacers are contained in the sealant 104.
There are three types of the sealant 104: a thermosetting type; an ultraviolet (UV)-curable type; and a thermosetting, UV-curable type. The type of the sealant 104 is selected as appropriate according to the method for forming the sealant 104. In a one drop fill (ODE) method (see, for example, Patent Document 1) which has been studied in recent years, it is preferable to use a thermosetting, UV-curable type sealant. The sealant 104 used to be formed by a screen printing method, but in recent years, is often formed by a dispenser method, which has high drawing accuracy and requires no screen printing plate. In the dispenser method, as shown in FIG. 8, a wider seal junction portion 117 is formed by connecting a drawing end point with a drawing starting point.
In the case where a plurality of switching devices, such as thin-film transistors (hereinafter referred to as TFTs), are formed in the liquid crystal cell 110, the first substrate 101 has a display region 106 having a display pixel group 105 where the TFTs and pixel electrodes are formed, a circuit portion 107 where a driving circuit and the like are formed, and a terminal region 108 where a plurality of terminals 109 are formed. On the other hand, a color filter, a counter electrode, and the like, which are not shown, are formed on the second substrate 102.
In general, the counter electrode on the second substrate 102 is rendered conductive with the first substrate 101 side through a so-called transfer (also referred to as a “common transfer”). That is, as shown in FIG. 8, a first electrode 111, made of a metal thin film and having a predetermined area, is formed in a corner of the first substrate 101 (see, for example, Patent Document 2). Moreover, a wiring 112, which has its one end connected to the first electrode 111 and the other end extended to the terminal region 108, is formed on the first substrate 101. The terminal 109 is formed at the other end of the wiring 112.
A transparent electrode, serving as a counter electrode (a second electrode) 113, is formed as a solid layer on the surface located on the first substrate 101 side of the second substrate 102, so as to extend substantially to the outer periphery of the second substrate 102. The second electrode 113 and the first electrode 111 are electrically connected to each other through a multiplicity of conductive members 114 contained in the sealant 104. A path from the second electrode 113, which is the counter electrode on the second substrate 102, via the conductive members 114, the first electrode 111, and the wiring 112, to the terminal 109 is formed in this manner. The “transfer” means an “electric connection structure between the first electrode 111 on the first substrate 101 and the second electrode 113 on the second substrate 102. In some cases, a plurality of transfers are provided in the liquid crystal cell 110.
Patent Document 1: Japanese Published Patent Application No. 2002-122870
Patent Document 2: Japanese Published Patent Application No. 2007-47507